Data from bisphosphonate long-term extension trials suggest that shorter term bisphosphonates may be equivalent to longer-term therapy for certain fractures types, and safety concerns have emerged about longer-term use of these agents, particularly osteonecrosis of the jaw and atypical femur fractures. Past studies had insufficient sample sizes for fracture and safety outcomes and very limited generalizability to complex patients in the community. To address these considerable osteoporosis evidence gaps, we propose a planning grant for a Pragmatic Clinical Trial (PCT) entitled the Effectiveness of DiscontinuinG bisphosphonatEs (EDGE) Study. EDGE will be a real world effectiveness trial of an initially estimated 4100 patients randomized to continuation or discontinuation of prior alendronate therapy. The specific aims of this planning grant are: 1) To collaborate with an advisory group of national osteoporosis, clinical trial, and community research experts established under the Medicare United with large Simple CLinical Trials Expanded network (MUSCLE) project to: a) finalize the EDGE study protocol with respect to the study population, recruitment plan, primary and secondary outcomes, data collection/analysis plan, and b) develop a manual of procedures and other study documents; 2) To develop effective linkages to Medicare data and the National Death Index (NDI) allowing for long-term surveillance of participants. The primary hypothesis to be tested in the EDGE trial is that among a postmenopausal women who have received 3 years of prior alendronate therapy at the time of enrollment non-vertebral fracture risk reduction in the 3 years following enrollment is non-inferio in women randomized to stop (intervention arm) compared to women randomized to continue alendronate therapy (comparator arm). UAB and its collaborators bring substantial expertise in conducting multi-site studies with Medicare claims and other large databases. In EDGE, we will partner with primary care and specialty health care networks, including the National Research Network (NRN), which cumulatively represent close to 10,000 providers and more than 10 million patients. We will draw on a preassembled team of expert advisors and expand our developing system for easy enrollment and surveillance of study subjects in PCTs. With linked Medicare claims and pharmacy data, EDGE will fill a major need for large osteoporosis effectiveness research at a considerably lower cost.